The Role of Angiogenesis-related Pathways in the Development of Port Wine Stains

1. Port wine stain (PWS) is a congenital, progressive vascular malformation of human skin involving the superficial vascular plexus that occurs in estimated 3-5 children per 1,000 live births. In childhood, PWS are flat red macules, but lesions tend to darken progressively to purple and, by middle age, often become raised as a result of the development of vascular nodules. Because most malformations occur on the face, PWS is a clinically significant problem in the majority of patients. 2. The late-stage cobblestoning appearance of PWS subjects is comprised by not only pronounced vascular ectasia with proliferation of thin and/or thick-walled vessels and their stroma, but also numerous epithelial, neural and mesenchymal hamartomatous abnormalities. Despite these histologic observations, the specific mechanisms involved in PWS nodular formation remains unclear. 3. In one nodular PWS subject, we found that phosphatidylinositol 3-kinases (PI3K)/protein kinase B (AKT) and phosphoinositide phospholipase C g subunit (PLC-g) were activated in both hypertrophic areas and nodules within the lesion. These observations led us to hypothesize that the PI3K pathway may play an important role in nodular formation.